> ## Documentation Index > Fetch the complete documentation index at: https://docs.auth.energy/llms.txt > Use this file to discover all available pages before exploring further. # List third-party users > Returns organisations registered to access consumer-specific tariff data (RTI Users). - The **public list** (name, ID, active status) is accessible without authentication. - **Registration data** (webhooks, contact details) is only returned to authenticated suppliers using their API key. ## OpenAPI ````yaml /tariff-interop/api/openapi-tariff.yaml get /v1/users openapi: 3.1.0 info: title: Tariff Interoperability API version: 0.1.1.AE description: > The Tariff Interoperability (TI) API lets Energy Smart Appliances, optimisers, and third-party services access standardised electricity tariff pricing data directly from GB energy suppliers. It is defined under the Retail Energy Code (REC) and mandated by the Smart Secure Electricity Systems (SSES) Programme. ## Two tiers of access | Tier | Who can use it | Auth required | |------|---------------|---------------| | **Public Tariff Pricing Data** | Any TI User | None | | **Consumer Specific Tariff Information** | Registered TI Users (RTI Users) with active consumer consent | OAuth 2.0 | contact: name: Auth Energy email: contact@auth.energy license: name: | © 2025 Retail Energy Code Company Ltd v0.1.0. All modifications and improves published © 2026 Auth Energy Ltd url: https://auth.energy/ servers: - url: https://register.tariff.interop description: > Central TI Register hosted by RECCo. Serves the `/v1/suppliers` and `/v1/users` endpoints only. The `v1` path prefix identifies the API version. - url: https://example-supplier.co.uk description: > Placeholder for a TI Energy Supplier's own hosted API. Each supplier runs their own instance at a URL they register with RECCo — discover it from `GET /suppliers`. Serves all `/v1/tariff`, `/v1/consent`, `/v1/webhook`, `/v1/report`, and outbound webhook endpoints. security: [] tags: - name: Registry description: >- Discover active suppliers and registered third-party users. Served by the central RECCo register. No authentication required for public data. - name: Tariffs description: >- Retrieve tariff listings and full pricing detail from a specific supplier. No authentication required. - name: Consumer Tariffs description: >- Retrieve tariff data tied to a specific consumer metering point. Requires OAuth 2.0 and active consumer consent. - name: Consent description: >- Register and revoke consumer consent linking a metering point to an RTI User via the OAuth 2.0 Authorisation Code flow. - name: Webhooks description: >- Manage webhook endpoints and receive push notifications when tariff data or consent state changes. - name: Reporting description: >- Submit periodic performance assurance metrics to RECCo (supplier obligation). paths: /v1/users: get: tags: - Registry summary: List third-party users description: > Returns organisations registered to access consumer-specific tariff data (RTI Users). - The **public list** (name, ID, active status) is accessible without authentication. - **Registration data** (webhooks, contact details) is only returned to authenticated suppliers using their API key. operationId: listRtiUsers parameters: - name: active in: query required: false description: When `true`, returns only currently active RTI Users. schema: type: boolean example: true responses: '200': description: A list of RTI User register entries. content: application/json: schema: type: object properties: data: type: array minItems: 1 items: $ref: '#/components/schemas/RtiUserRegisterEntry' example: data: - user_id: usr_c7e2f1a03b4d4e5f8a9b1c2d3e4f5a6b name: Example Optimiser Ltd display_name: Optimiser status: active last_modified: '2026-10-15T08:30:00.000Z' support: tariff-support@optimiser.co.uk '401': $ref: '#/components/responses/Unauthorized' '500': $ref: '#/components/responses/InternalServerError' security: - {} - supplierApiKey: [] servers: - url: https://register.tariff.interop description: Central TI Register (RECCo) components: schemas: RtiUserRegisterEntry: type: object description: > An RTI User's entry in the TI User Register. Registration data (webhook URL, contact details) is only returned to authenticated suppliers. required: - user_id - name - display_name - last_modified - support - status properties: user_id: $ref: '#/components/schemas/UserId' name: type: string maxLength: 200 description: Organisation's legal name. example: Cucumber Energy Optimiser Ltd display_name: type: string maxLength: 100 description: Short trading name displayed to consumers. example: Optimiser status: $ref: '#/components/schemas/UserStatus' support: $ref: '#/components/schemas/SupportContact' example: tariff-support@optimiser.co.uk last_modified: $ref: '#/components/schemas/Timestamp' UserId: type: string format: uuid pattern: ^usr_[0-9a-f]{32}$ description: > Compact UUID generated by RECCo uniquely identifying the user with `usr_`. example: usr_550e8400e29b41d4a716446655440000 UserStatus: type: string description: The status of the user. enum: - active - suspended - disabled - removed example: active SupportContact: type: string description: >- Support contact information for Users - email, url, telephone is acceptable. example: tariff-support@acme.co.uk Timestamp: type: string format: date-time description: ISO 8601 datetime with millisecond precision. example: '2026-11-01T10:00:00.000Z' ErrorResponse: type: object required: - code - message properties: code: type: string description: Machine-readable error code. example: tariff_not_found message: type: string description: Human-readable error description. example: No tariff found for the given tariff_id and supplier MPID. details: type: string description: Additional context to help diagnose the issue. example: >- tariff_id a1b2c3d4-e5f6-7890-abcd-ef1234567890 does not exist for supplier SEBD. responses: Unauthorized: description: 401 — Missing or invalid authentication credentials. content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' InternalServerError: description: 500 — Unexpected server error. Retry within the 72-hour buffer window. content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' securitySchemes: supplierApiKey: type: apiKey description: > API key issued to TI Energy Suppliers for accessing restricted register data and submitting performance reports. Credentials are valid for 2 years and are distributed via a one-time URL from the Code Manager. in: header name: X-Supplier-API-Key ````